Conventionally, a common vane compressor is proposed (refer to, e.g., Patent Literature 1). The vane compressor has a structure in which a vane is fitted in a vane groove formed at one location or each of a plurality of locations in a rotor portion of a rotor shaft (unitary formation of the columnar rotor portion that rotates within a cylinder and a shaft that transmits torque to the rotor portion being referred to as the rotor shaft), and a vane tip slides while contacting the inner peripheral surface of the cylinder.
A different vane compressor is proposed (refer to, e.g., Patent Literature 2). In the vane compressor, an inside of a rotor shaft is formed to be hollow, and a fixed shaft for vanes is disposed in the inside of the rotor shaft. The vanes are rotatably attached to the fixed shaft. Further, each vane is held rotatably with respect to a rotor portion through a pair of semicircular-bar-shaped supporting members in the vicinity of an outer peripheral part of the rotor portion.